Ute Ladies’-Tresses Fact Sheet ( diluvialis)

Habitat Description Ute ladies’-tresses is an obligate mesophyte, usually growing in the cobbly sand, shingly sand, gravelly sand or sandy loam of wet meadows, stream or lake margins, abandoned stream meanders, riparian sandbars and subir- rigated springs and seeps. Occasionally it may grow in moist swales within Populus angustifolia – Cornus sericea woodlands, or even in irrigated pastureland. It avoids the shade of woody shrubs and trees, especially Tamarix-dominated sites, and prefers open, sunny forb / graminoid-dominated habitats instead. Elevational amplitude is between 4,400 and 6,810 ft amsl.

Associated Associated species vary with habitat type, whether riparian, lacustrine, seep, spring or subirrigated meadow. Green populations are usually associated with , Cornus sericea, Equisetum laeviga- tum, various forbs and scattered stands of Salix exigua (Fertig et al., 2005).

Similar and Related Species Ute ladies’-tresses is most similar to hooded ladies’-tresses (S. romanzoffiana), from which it is an allopoly- ploid derivative. The easiest way to distinguish them is by the flower. Hooded ladies’-tresses has more Species Description deeply constricted, fiddle-shaped lip petals, sepals fused for at least half their length into a hood-like tube, and pubescence of short hairs along the stem and ; Ute ladies’-tresses has lip petals merely Ute ladies’-tresses consists of a perennating narrowed at the middle, sepals fused only at the base and only sparse pubescence. In addition, the flowers underground rhizome-mycorrhizal complex tend to be more congested on the spike of hooded ladies’-tresses, less so on the spike of Ute ladies’-tresses; and seasonal aerial shoots. The rhizome / ascending-appressed to the stem in hooded ladies’-tresses, more spreading in Ute ladies’-tresses; and closed mycorrhizal complex is thickened and in hooded ladies’s-tresses, gaping-ringent in Ute ladies’-tresses. Ecologically, hooded ladies’-tresses typi- tuberous. The aerial shoots are erect, cally occurs in from montane to timberline elevations throughout the Rocky Mountains; Ute la- sparsely glandular-pubescent, 12 to 60 cm dies’-tresses typically occurs in lower elevations. The other antecedent, Great Plains ladies’- tall. Basal leaves are narrowly linear, up to tresses (S. magnicamporum), occurs from eastward, and therefore does not concern us in VFO. 1 cm wide and 28 cm long, and persistent at anthesis. Cauline leaves become progres- sively smaller up the stem. The stem grades Phenology and Reproductive Biology into a sparsely pubescent spike, 3 to 15 cm long, consisting of 7 to 32 small white or Ute ladies’-tresses flowers from late-July through August. Long-tongue () and ivory-colored flowers arranged in a 3- (Bombus) are the most important pollinators of this species (Sipes & Tepedino, 1995). Fruit matures and ranked spiral. Individual flowers are 7.5 to dehisces by September or October. Like most other orchids, the seeds are submacroscopic and wind- 15 mm long and faintly vanilla-scented, dispersed. Seed requires surficially moist soil throughout the growing season. Seed germina- slightly gaping at the mouth. The sepals are tion and seedling establishment also require symbiosis with a mycorrhizal fungus. It is believed the is separate or fused only at the base and are mycorrhizae-dependent throughout all phases of its life. The orchid appears tolerant of disturbance caused mostly ascending or perpendicular to the by natural fluvial processes. stem; the dorsal sepal forms a hood, and the lateral sepals often spread abruptly from the base of the flower. The petals are also Current Distribution ascending or perpendicular to the stem; the lip petal is oval to lanceolate, narrowed at Ute ladies-tresses has been reported from , , , Nebraska, , , , the middle, and has crispy-wavy margins. and , with the greatest concentration of individuals in northeast Utah. In VFO, potential and Fruits are cylindric capsules with numerous suitable habitat for SPDI6 occurs in areas throughout Daggett, Duchesne, and Uintah counties. tiny, submacroscopic seeds.